Chrysanthemum plant named `White Blush`

ABSTRACT

A Chrysanthemum plant named White Blush particularly characterized by its flat capitulum form; daisy capitulum type; white ray floret color, with a cream-white color of the immature ray florets; diameter across face of capitulum of 114 to 121 mm when fully opened, when grown as a pinched disbudded pot mum; photoperiodic flowering response to short days of 49 to 55 days; plant height, with 20 to 22 long days after sticking unrooted cuttings, and with 1 to 2 applications of 2500 ppm B-9 SP, ranges from 20 to 30 cm when grown as a pinched pot mum with 4 cuttings in a 15 cm pot; branching pattern is semi-spreading, each plant having 3 to 5 laterals after pinch; and recommended as a disbudded pot mum.

The present invention comprises a new and distinct cultivar ofChrysanthemum, botanically known as Dendranthema grandiflora, andreferred to by the cultivar name White Blush.

White Blush, identified as 5661 (86-627D02), is a product of a mutationinduction program. The new cultivar was discovered and selected byCornelis P. VandenBerg on Jul. 23, 1990, in a controlled environment inSalinas, Calif., as one flowering plant within a flowering blockestablished as rooted cuttings from stock plants which had been exposedas unrooted cuttings to an X-ray source of 2000 rads in Fort Myers,Fla., on Jan. 25, 1990. The irradiated parent cultivar was the cultivaridentified as Blush, disclosed in U.S. Plant Pat. No. 7,985, anddescribed as a disbud daisy pot mum with flat capitulum form; soft pinkray floret color; diameter across face of capitulum of 114 to 140 mmwhen fully opened, when grown as a pinched disbudded pot mum; floweringresponse period of 47 to 55 days after start of short days; plant heightof 23 to 28 cm with 1 to 3 applicatins of 2500 ppm B-9 SP when grown asa pinched pot mum in a 15 cm pot; semi-spreading branching pattern, with3 to 5 laterals after pinch; and recommended as a disbudded pot mum. Theforegoing description of Blush has a somewhat wider range ofmeasurements than the description of Blush in the noted plant patent.This is based on continued flowering trials of Blush after preparing andfiling the patent application for Blush.

The irradiation program resulting in White Blush has as its primaryobjective the expansion of color ranges of the parent cultivar Blush.The irradiation program comprised irradiating cuttings of the parentcultivar at irradiation levels of 1500, 1750 and 2000 rads. A total of1433 cuttings harvested from a total of 225 irradiated plants wereplanted on May 28, May 21 and May 14, 1990, respectively. Of these, 19initial selections were made, which selections were then revegetated andreflowered. Three consecutive flowerings resulted in discarding 12 ofthe original 19 selections on Apr. 23, 1991. Seven selections wereratained and given PI (Possible Introduction) status. Continuedflowering trials resulted in discarding 3 of the 7 remaining selections,and the decision to introduce 2 of the remaining selections in NorthAmerica and Europe as White Blush and Coral Blush. Coral Blush isdisclosed in pending application Ser. No. 08/296,446.

The remaining two selections were designated Pink Blush and OrangeBlush. All four selections were introduced in Europe at the same time.Pink Blush and Orange Blush were introduced in the United States oneyear after introduction in Europe. Pink Blush is the subject ofcopending application Ser. No. 08/331,863 and Orange Blush is thesubject of copending application Ser. No. 08/331,856.

The first act of asexual reproduction of White Blush was accomplishedwhen vegetative cuttings were taken from the initial selection in Sep.1990 in a controlled environment in Salinas, Calif., by techniciansworking under supervision of Cornelis P. VandenBerg.

Horticultural examination of controlled flowerings of successiveplantings has shown that the unique combination of characteristics asherein disclosed for White Blush are firmly fixed and are retainedthrough successive generations of asexual reproduction.

White Blush has not been observed under all possible environmentalconditions. The phenotype may vary significantly with variations inenvironment such as temperature, light intensity and daylength, without,however, any variance in genotype.

The following observations, measurements and comparisons describe plantsgrown in Salinas, Calif. under greenhouse conditions which approximatethose generally used in comemrcial greenhouse practice.

The following traits have been repeatedly observed and are determined tobe basic characteristics of White Blush, which, in combination,distinguish this Chrysanthemum as a new and distinct cultivar:

1. Flat capitulum form.

2. Daisy capitulum type.

3. White ray flroet color, with a cream-white color of the immature rayflorets.

4. Diameter across face of capitulum of 114 to 121 mm when fully opened,when grown as a pinched disbudded pot mum.

5. Photoperiodic flowering response to short days of 49 to 55 days.

6. Plant height, with 20 to 22 long days after sticking unrootedcuttings and with 1 to 2 applications of 2500 ppm B-9 SP, ranges from 20to 30 cm when grown as a pinched pot mum with 4 cuttings in a 15 cm pot.

7. Branching pattern is semi-spreading, each plant having 3 to 5laterals after pinch.

8. Recommended as a disbudded pot mum.

The accompanying photographic drawing is a top perspective view of apotted mum of White Blush, with 4 cuttings in a 15 cm pot, with thecolors being as nearly true as possible with illustrations of this type.

Of the commercial cultivars known to the inventor, the most similar incomparison to WHite Blush is the parent cultivar Blush. All traits ofWhite Blush are similar to those of Blush, except for the ray floretcolor. The ray floret color of White Blush is white, while the rayfloret color of Blush is soft pink. White Blush is distinguished fromCoral Blush by ray floret color.

In the following description color references are made to The RoyalHorticultural Society Colour Chart. The color values were determined onplant material grown as a pinched spray pot mum in Salinas, Calif. onJul. 28, 1992.

Classification

Botanical.--Dendranthema grandiflora cv White Blush.

Commercial.--Flat daisy disbud pot mum.

INFLORESCENCE

A. Capitulum:

Form.--Flat.

Type.--Daisy.

Diameter across face.--114 to 121 mm when fully opened.

Corolla of ray florets

Color (general tonality form a distance of three meters).--White.

Color (upper surface).--Mature 155D, immature 155A to 1D.

Color (under surface).--155D.

Shape.--Straight, pointed, slightly ribbed.

C. Corolla of disc florets:

Color (mature).--7B.

Color (immature).--144A to 144B.

D. Reproductive organs:

Androecium.--Present on disc florets only; scant pollen.

Gynoecium.--Present on both ray and disc florets.

PLANT

A. General appearance:

Height.--20 to 30 cm when grown as a pinched pot mum with 20 to 22 longdays prior to start of short days, with 1 to 2 applications of 2500 ppmB-9 SP.

Branching pattern.--Semi-spreading, with 3 to 5 laterals after pinch.

B. Foliage:

Color (upper surface).--147A.

Color (under surface).--147B.

Shape and size.--Moderately lobed and serrated; leaves are 75-85 mm longand 45-50 mm wide.

I claim:
 1. A new and distinct Chrysanthemum plant named White Blush, asdescribed and illustrated.